Normalise route naming scheme to 'Route X (Region)' format

Standardise 426 inconsistent route names across 33 seed data files
(game data + boss files). Converts 'Region Route X' prefix style and
'Route X - Region' dash style to the consistent 'Route X (Region)' format.

Resolves beans-r48e.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/src/app/seeds/data/soulsilver.json

@@ -14056,7 +14056,7 @@
     ]
   },
   {
-    "name": "Kanto Route 2",
+    "name": "Route 2 (Kanto)",
     "order": 132,
     "encounters": [],
     "children": [